CVE-2026-64578

CVE-2026-64578 affects the Linux kernel ksmbd SMB2 handling. A compound (chained) SMB2 request could trigger a slab-out-of-bounds read when ksmbd_smb2_check_message() reads the StructureSize2 field at offset 64 without first ensuring the compound element is large enough. The vulnerable path occur...

EUVD-2026-53272

In the Linux kernel, the following vulnerability has been resolved: ksmbd: validate compound request size before reading StructureSize2 When ksmbd validates a compound chained SMB2 request, ksmbdsmb2checkmessage reads pdu-StructureSize2 without first checking that the compound element is large...

SUSE CVE-2026-64396

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix UAF of struct filelock in SMB2LOCK deferred-lock cancellation When a blocking byte-range lock request is deferred in the FILELOCKDEFERRED path, ksmbd registers the asynchronous work into the connection's asyncrequests...

SUSE CVE-2026-64437

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free of a deferred filelock on SMB2CLOSE then SMB2CANCEL Commit f580d27e8928 "ksmbd: fix use-after-free of a deferred filelock on double SMB2CANCEL" made smb2cancel skip a work whose state is...

CVE-2026-64385

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix double-free in SMB2ioctl replay A response-bearing attempt can return a replayable error and free its response buffer. If SMB2ioctlinit fails before the next send, cleanup retains the previous buffer type and fre...

CVE-2026-64257

In the Linux kernel, the following vulnerability has been resolved: smb: client: reject overlapping data areas in SMB2 responses Commit 53b7c271f06b "smb: client: restrict implied bcc0 exemption to responses without data area" restricted the implied bcc0 length exception to responses without a da...

UBUNTU-CVE-2026-64437

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free of a deferred filelock on SMB2CLOSE then SMB2CANCEL Commit f580d27e8928 "ksmbd: fix use-after-free of a deferred filelock on double SMB2CANCEL" made smb2cancel skip a work whose state is...

UBUNTU-CVE-2026-64394

In the Linux kernel, the following vulnerability has been resolved: ksmbd: add a WRITEDAC/WRITEOWNER check to SMB2 SETINFO SECURITY commit cc57232cae23 "ksmbd: fix FSCTL permission bypass by adding a permission check for FSCTLSETSPARSE" added a fp-daccess gate to fsctlsetsparse and noted that...

UBUNTU-CVE-2026-64390

In the Linux kernel, the following vulnerability has been resolved: ksmbd: track the connection owning a byte-range lock SMB2LOCK adds each granted byte-range lock to both the file lock list and the lock list of the connection which handled the request. The final close and durable handle paths,...

CVE-2026-64437

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free of a deferred filelock on SMB2CLOSE then SMB2CANCEL Commit f580d27e8928 "ksmbd: fix use-after-free of a deferred filelock on double SMB2CANCEL" made smb2cancel skip a work whose state is...

CVE-2026-64437

CVE-2026-64437 affects the ksmbd component of the Linux kernel. A use-after-free in a deferred file_lock can be triggered by a sequence of SMB2_CLOSE followed by SMB2_CANCEL, allowing an authenticated SMB client to cause a kernel crash (denial of service) via the freed file_lock. The root cause i...

EUVD-2026-48781

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix use-after-free of a deferred filelock on SMB2CLOSE then SMB2CANCEL Commit f580d27e8928 "ksmbd: fix use-after-free of a deferred filelock on double SMB2CANCEL" made smb2cancel skip a work whose state is...

CVE-2026-64398 ksmbd: add a permission check for FSCTL_SET_ZERO_DATA

In the Linux kernel, the following vulnerability has been resolved: ksmbd: add a permission check for FSCTLSETZERODATA FSCTLSETZERODATA in smb2ioctl destroys file data via ksmbdvfszerodata - vfsfallocatePUNCHHOLE/ZERORANGE after checking only the share-level KSMBDTREECONNFLAGWRITABLE, with no...

EUVD-2026-48942

In the Linux kernel, the following vulnerability has been resolved: ksmbd: add a permission check for FSCTLSETZERODATA FSCTLSETZERODATA in smb2ioctl destroys file data via ksmbdvfszerodata - vfsfallocatePUNCHHOLE/ZERORANGE after checking only the share-level KSMBDTREECONNFLAGWRITABLE, with no...

EUVD-2026-48940

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix UAF of struct filelock in SMB2LOCK deferred-lock cancellation When a blocking byte-range lock request is deferred in the FILELOCKDEFERRED path, ksmbd registers the asynchronous work into the connection's asyncrequests...

CVE-2026-64396

In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix UAF of struct filelock in SMB2LOCK deferred-lock cancellation When a blocking byte-range lock request is deferred in the FILELOCKDEFERRED path, ksmbd registers the asynchronous work into the connection's asyncrequests...

CVE-2026-64394 ksmbd: add a WRITE_DAC/WRITE_OWNER check to SMB2 SET_INFO SECURITY

In the Linux kernel, the following vulnerability has been resolved: ksmbd: add a WRITEDAC/WRITEOWNER check to SMB2 SETINFO SECURITY commit cc57232cae23 "ksmbd: fix FSCTL permission bypass by adding a permission check for FSCTLSETSPARSE" added a fp-daccess gate to fsctlsetsparse and noted that...

EUVD-2026-48938

In the Linux kernel, the following vulnerability has been resolved: ksmbd: add a WRITEDAC/WRITEOWNER check to SMB2 SETINFO SECURITY commit cc57232cae23 "ksmbd: fix FSCTL permission bypass by adding a permission check for FSCTLSETSPARSE" added a fp-daccess gate to fsctlsetsparse and noted that...

CVE-2026-64394 ksmbd: add a WRITE_DAC/WRITE_OWNER check to SMB2 SET_INFO SECURITY

In the Linux kernel, the following vulnerability has been resolved: ksmbd: add a WRITEDAC/WRITEOWNER check to SMB2 SETINFO SECURITY commit cc57232cae23 "ksmbd: fix FSCTL permission bypass by adding a permission check for FSCTLSETSPARSE" added a fp-daccess gate to fsctlsetsparse and noted that...

CVE-2026-64394

Summary: CVE-2026-64394 relates to the Linux kernel ksmbd SMB2 SET_INFO SECURITY path. The fix adds a per-handle access gate to prevent rewriting security descriptors when the handle lacks WRITE_DAC/WRITE_OWNER. Previously, SMB2_SET_INFO with InfoType SMB2_O_INFO_SECURITY could re-permission a fi...